27 research outputs found
Next-to-Minimal Supersymmetric Model Higgs Scenarios for Partially Universal GUT Scale Boundary Conditions
We examine the extent to which it is possible to realize the NMSSM "ideal
Higgs" models espoused in several papers by Gunion et al in the context of
partially universal GUT scale boundary conditions. To this end we use the
powerful methodology of nested sampling. We pay particular attention to whether
ideal-Higgs-like points not only pass LEP constraints but are also acceptable
in terms of the numerous constraints now available, including those from the
Tevatron and -factory data, and the relic density .
In general for this particular methodology and range of parameters chosen, very
few points corresponding to said previous studies were found, and those that
were found were at best away from the preferred relic density value.
Instead, there exist a class of points, which combine a mostly singlet-like
Higgs with a mostly singlino-like neutralino coannihilating with the lightest
stau, that are able to effectively pass all implemented constraints in the
region . It seems that the spin-independent direct detection cross
section acts as a key discriminator between ideal Higgs points and the hard to
detect singlino-like points.Comment: 22 pages, 15 figure
Impact of Higgs physics on the parameter space of the μνSSM
Given the increasing number of experimental data, together with the precise measurement of the properties of the Higgs boson at the LHC, the parameter space of supersymmetric models starts to be constrained. We carry out a detailed analysis of this issue in the framework of the μνSSM. In this model, three families of right-handed neutrino superfields are present in order to solve the μ problem and simultaneously reproduce neutrino physics. The new couplings and sneutrino vacuum expectation values in the μνSSM induce new mixing of states, and, in particular, the three right sneutrinos can be substantially mixed with the neutral Higgses. After diagonalization, the masses of the corresponding three singlet-like eigenstates can be smaller or larger than the mass of the Higgs, or even degenerated with it. We analyze whether these situations are still compatible with the experimental results. To address it we scan the parameter space of the Higgs sector of the model. In particular, we sample the μνSSM using a powerful likelihood data-driven method, paying special attention to satisfy the constraints coming from Higgs sector measurements/limits (using HiggsBounds and HiggsSignals), as well as a class of flavor observables such as B and μ decays, while muon g- 2 is briefly discussed. We find that large regions of the parameter space of the μνSSM are viable, containing an interesting phenomenology that could be probed at the LHCThe work of EK and CM was supported in part by the Spanish Agencia Estatal de Investigación through the grants FPA2015-65929-P (MINECO/FEDER, UE), PGC2018-095161-B-I00 and IFT Centro de Excelencia Severo Ochoa SEV-2016-0597. The work of EK was funded by Fundación La Caixa under ‘La Caixa-Severo Ochoa’ international predoctoral grant. The work of DL was supported by the Argentinian CONICET, and also acknowledges the support of the Spanish grant FPA2015-65929-P (MINECO/FEDER, UE). RR acknowledges partial funding/support from the Elusives ITN (Marie Sklodowska-Curie grant agreement No 674896), the “SOM Sabor y origen de la Materia” (FPA 2017-85985-P) and the Spanish MINECO Centro de Excelencia Severo Ochoa del IFIC program under grant SEV-2014-0398. EK, CM, DL and RR also acknowledge the support of the Spanish Red Consolider MultiDark FPA2017-90566-RED
Novel signatures for vector-like quarks
We consider supersymmetric extensions of the standard model with a vector-like doublet (T B) of quarks with charge 2/3 and −1/3, respectively. Compared to non-supersymmetric models, there is a variety of new decay modes for the vector-like quarks, involving the extra scalars present in supersymmetry. The importance of these new modes, yielding multi-top, multi-bottom and also multi-Higgs signals, is highlighted by the analysis of several benchmark scenarios. We show how the triangles commonly used to represent the branching ratios of the ‘standard’ decay modes of the vector-like quarks involving W, Z or Higgs bosons can be generalised to include additional channels. We give an example by recasting the limits of a recent heavy quark search for this more general case.The work of J.A. Aguilar-Saavedra has been supported by MINECO Projects FPA 2016-
78220-C3-1-P and FPA 2013-47836-C3-2-P (including ERDF), and by Junta de Andaluc a
Project FQM-101. The work of D.E. L opez-Fogliani has been supported by the Argentinian
CONICET. The work of C. Mu~noz has been supported in part by the Programme SEV-
2012-0249 `Centro de Excelencia Severo Ochoa'. D.E. L opez-Fogliani and C. Mu~noz also
acknowledge the support of the Spanish grant FPA2015-65929-P (MINECO/FEDER, UE),
and MINECO's Consolider-Ingenio 2010 Programme under grant MultiDark CSD2009-
00064
The Higgs sector of the munuSSM and collider physics
The SSM is a supersymmetric standard model that accounts for light
neutrino masses and solves the problem of the MSSM by simply using
right-handed neutrino superfields. Since this mechanism breaks R-parity, a
peculiar structure for the mass matrices is generated. The neutral Higgses are
mixed with the right- and left-handed sneutrinos producing 88 neutral
scalar mass matrices. We analyse the Higgs sector of the SSM in detail,
with special emphasis in possible signals at colliders. After studying in
general the decays of the Higges, we focus on those processes that are genuine
of the SSM, and could serve to distinguish it from other supersymmetric
models. In particular, we present viable benchmark points for LHC searches. For
example, we find decays of a MSSM-like Higgs into two lightest neutralinos,
with the latter decaying inside the detector leading to displaced vertices, and
producing final states with 4 and 8 -jets plus missing energy. Final states
with leptons and missing energy are also found.Comment: Final version to appear in JHEP. The discussion on signals at
colliders, expanded. 33 pages, 8 figures and 9 table
Gamma-ray detection from gravitino dark matter decay in the SSM
The SSM provides a solution to the -problem of the MSSM and
explains the origin of neutrino masses by simply using right-handed neutrino
superfields. Given that R-parity is broken in this model, the gravitino is a
natural candidate for dark matter since its lifetime becomes much longer than
the age of the Universe. We consider the implications of gravitino dark matter
in the SSM, analyzing in particular the prospects for detecting gamma
rays from decaying gravitinos. If the gravitino explains the whole dark matter
component, a gravitino mass larger than 20 GeV is disfavored by the isotropic
diffuse photon background measurements. On the other hand, a gravitino with a
mass range between 0.1-20 GeV gives rise to a signal that might be observed by
the FERMI satellite. In this way important regions of the parameter space of
the SSM can be checked.Comment: Final version to appear in JCAP, 13 pages, 3 figure
Dark matter candidates in the NMSSM with RH neutrino superfields
R-parity conserving supersymmetric models with right-handed (RH) neutrinos are very appealing since they could naturally explain neutrino physics and also provide a good dark matter (DM) candidate such as the lightest supersymmetric particle (LSP). In this work we consider the next-to-minimal supersymmetric standard model (NMSSM) plus RH neutrino superfields, with effective Majorana masses dynamically generated at the electroweak scale (EW). We perform a scan of the relevant parameter space and study both possible DM candidates: RH sneutrino and neutralino. Especially for the case of RH sneutrino DM we analyse the intimate relation between both candidates to obtain the correct amount of relic density. Besides the well-known resonances, annihilations through scalar quartic couplings and coannihilation mechanisms with all kind of neutralinos, are crucial. Finally, we present the impact of current and future direct and indirect detection experiments on both DM candidates.Instituto de Física La Plat
Dark matter candidates in the NMSSM with RH neutrino superfields
R-parity conserving supersymmetric models with right-handed (RH) neutrinos are very appealing since they could naturally explain neutrino physics and also provide a good dark matter (DM) candidate such as the lightest supersymmetric particle (LSP). In this work we consider the next-to-minimal supersymmetric standard model (NMSSM) plus RH neutrino superfields, with effective Majorana masses dynamically generated at the electroweak scale (EW). We perform a scan of the relevant parameter space and study both possible DM candidates: RH sneutrino and neutralino. Especially for the case of RH sneutrino DM we analyse the intimate relation between both candidates to obtain the correct amount of relic density. Besides the well-known resonances, annihilations through scalar quartic couplings and coannihilation mechanisms with all kind of neutralinos, are crucial. Finally, we present the impact of current and future direct and indirect detection experiments on both DM candidates.Fil: López Fogliani, Daniel E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Perez, Andres Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Ruiz de Austri, Roberto. Consejo Superior de Investigaciones Científicas; España. Universidad de Valencia; España. Instituto de Física Corpuscular; Españ
Analysis of the parameter space and spectrum of the SSM.
40 pages, 12 figures.-- Pre-print archive.The μνSSM is a supersymmetric standard model that solves the μ problem of the MSSM using the R-parity breaking couplings between the right-handed neutrino superfields and the Higgses in the superpotential, λi hat nucihat Hdhat Hu. The μ term is generated spontaneously through sneutrino vacuum expectation values, μ = λilangletilde nucirangle, once the electroweak symmetry is broken. In addition, the couplings κijkhat nucihat nucjhat nuck forbid a global U(1) symmetry avoiding the existence of a Goldstone boson, and also contribute to spontaneously generate Majorana masses for neutrinos at the electroweak scale. Following this proposal, we have analysed in detail the parameter space of the μνSSM. In particular, we have studied viable regions avoiding false minima and tachyons, as well as fulfilling the Landau pole constraint. We have also computed the associated spectrum, paying special attention to the mass of the lightest Higgs. The presence of right and left-handed sneutrino vacuum expectation values leads to a peculiar structure for the mass matrices. The most important consequence is that neutralinos are mixed with neutrinos, and neutral Higgses with sneutrinos.D.E. L´opez-Fogliani thanks the Science and Technology Facilities Council (STFC) for financial
support. C. Mu˜noz and R. Ruiz de Austri were supported in part by the MICINN
under Proyectos Nacionales FPA2006-05423 and FPA2006-01105, and by the European
Union under the RTN program MRTN-CT-2004-503369. We thank the project HEPHACOS
P-ESP-00346 of the Comunidad de Madrid. The use of the ciclope cluster of
the IFT-UAM/CSIC is also acknowledged. D.E. L´opez-Fogliani also wants to thank S.
Fauquier for her support.Peer reviewe